Metropoulos Forum

Hi guys,

Some things came up, and I delayed buying my JTM45 kit awhile back. My goal is to get as close as I can to the tone Eric Clapton got on the John Mayall's Bluesbreakers with Eric Clapton album, i.e. the "Beano" album. I had considered buying a Marshall Bluesbreaker and modding it, and I also thought about buying a Ceriatone Bluesbreaker combo. But I really like the idea of building my own amp, so the Metro it is.

I'm planning on using the stock Metro kit, but with the Sozo Mustard upgrade. My big question would be if you all recommend tweaking the stock Metro kit to get me closer to the Beano tone? Would different transformers work better? Should I tweak any of the values of anything? I realize that EC probably didn't have a modded amp, but with the way you guys have decoded the EVH Brown Sound, I wanted to ask for advice about the Beano tone.

Thanks, gents.
Brad

Build the head to the specs included with the kit, get some good low wattage alnico speakers like scumnicos, a good treble booster, and a Paul with some low output paf's. That will getcha there for the most part. Then after you get that amp broken in good, you can tweak to taste, but you'll probably love it as is. The "Beano" tone isn't the most elusive tone to get. IMO. But it is sweet isn't it? One more thing, preamp tubes can make a huge difference in the tone, so later on you'll probably want some nos glass. Good luck, you'll find tons of great help here.

Thanks for the advice. I have a 59RI Les Paul and a Keeley Java Boost, so I have kind of a head start. I've read some really good reviews of the Scumnicos as well, so those are definite possibilities. As for tubes, I do have a small collection ready to go. I have a few old Mullard preamp tubes, as well as 2 Mullard GZ34s. For power tubes, I have a couple pairs of Groove Tube KT66HPs. Those were supposed to be reissues of the old Gold Lions.

I've only played one JTM45, but it was one of the PCB Marshall reissues through a V30-loaded cabinet at a Guitar Center. It didn't sound great, but it wasn't bad either. I attribute a lot of that to the Vintage 30s. (I just can't stand those...) Plus, it was in a GC, so it's kind of hard to get a good read on gear anyway. But there are so many great recordings of the JTM, that I just know a good one will be killer.

Thanks,
Brad

F#m7 wrote:Build the head to the specs included with the kit, get some good low wattage alnico speakers like scumnicos, a good treble booster, and a Paul with some low output paf's. That will getcha there for the most part. Then after you get that amp broken in good, you can tweak to taste, but you'll probably love it as is. The "Beano" tone isn't the most elusive tone to get. IMO. But it is sweet isn't it? One more thing, preamp tubes can make a huge difference in the tone, so later on you'll probably want some nos glass. Good luck, you'll find tons of great help here.

What F#m7 said, except forget about the Rangemaster. Once you get the Scumnicos in there, you won't need to think about anything else to complete the picture. I would consider a power transformer with a slightly higher B+ though. George's stock PT gives you around 400V, but the originals typically had 440-450. Marstran's PT comes closer. Other than that, no need to tweak anything, really.

shakti wrote:What F#m7 said, except forget about the Rangemaster. Once you get the Scumnicos in there, you won't need to think about anything else to complete the picture. I would consider a power transformer with a slightly higher B+ though. George's stock PT gives you around 400V, but the originals typically had 440-450. Marstran's PT comes closer. Other than that, no need to tweak anything, really.

I have Georges PT, and I got a B+ of around 420v last time I checked.

What's your wall voltage? I'm sure they vary a bit, but around 400 seems to be the number I've seen here most often. Mine would even drop to 390 when the wall voltage was a little below nominal value.

But some people will prefer the lower voltage too, of course. The amp sounded excellent in stock form as well, but I prefer the slightly brighter and livelier feel with a higher voltage.

I have no idea what the wall voltage was when I measured it. I'll have to check. But what you say is true, I have thought about trying a different PT to get it up in the 450v range.

Hi guys,
I've been doing some reading, and it appears that the first Bluesbreaker combos were originally issued with a Radio Spares transformer. But there is a lot of conjecture that EC's had a Drake tranny installed. Is George's transformer based on the RS Deluxe? Is the Marstran similar to the Drake?
Thanks,
Brad

George and Marstran both have their own versions of both the Drake and the RS output transformers. But in the Metro JTM45 kit, the Drake version is the standard OT.

For the Clapton Beano tone, the Drake is the one you want. Nobody knows with 100% certainty which type OT Clapton's Bluesbreaker had, but I've yet to hear anyone say the RS sounds closer, it's always the Drake people go for when trying to get that tone. Taking into account the timeframe that Clapton's amp would have been built (sometime between late, late '65 and Feb/March '66), it seems very unlikely that the amp would have had the RS OT, as Marshall had long since moved on to the Drake OTs by that time.

shakti wrote:George and Marstran both have their own versions of both the Drake and the RS output transformers. But in the Metro JTM45 kit, the Drake version is the standard OT.

For the Clapton Beano tone, the Drake is the one you want. Nobody knows with 100% certainty which type OT Clapton's Bluesbreaker had, but I've yet to hear anyone say the RS sounds closer, it's always the Drake people go for when trying to get that tone. Taking into account the timeframe that Clapton's amp would have been built (sometime between late, late '65 and Feb/March '66), it seems very unlikely that the amp would have had the RS OT, as Marshall had long since moved on to the Drake OTs by that time.

Right that is my opinion too.

Don't forget the speakers the series I Bluesbreakers all had alnico speakers and EC's amp was one of the first series II combos so most likely had alnicos as well. So an open back cab with Scumnicos will get you as close as you can get.

OK guys, thanks for the input. It looks like I'm going to go with the stock JTM kit, except I'll upgrade to the Sozo Mustards. I already have a nice open-back Avatar 212 that would work great with a couple Scumnicos. My last real question before I jump in would be about the LarMar PPIMV. My Plexi has that, and it works great for that amp. Have any of you used it with the JTM45 with similar results?

Thanks again,
Brad

I have the Lar/Mar and am pleased with it. ANything below 1/2 way is a bit of a compromise, but it's more than livable and better sounding to me than attenuators. Nice thing, if you don't care for it once you put it in, it's easily removed, or just leave it full up for bypass.

Definitely worth the low bucks and quick mod. Anything I build from this point will likely get one.

if you look at my signature...in the site there are a lot of BB pic..and you will see that the late stile 1 combo already come out of factory with 20w greenback..so i think that eric used greenback speaker..
also if you think well and if you have the chance to try...a kt66 with 450 volts on plate sounds a lot like a 6L6 with 370 - 390 volts...
obviously at the same voltage they sound different but with lower voltage the 6L6 cut the treble and mids and lower mids are more evident...just like a Kt66...ok they 're not identical but very similar...
Also if you put a SS recto in a lower voltage amp it sounds like a tube rect with more current...
plus the new reissue have a 150k plate resitor on normal channel that added to the tremolo circuit (that operates on normal channel) gives more mids and more gain.
The result is that I (i'm speaking about myself..other people can't condivide my ideas) have take my BBRI, put SED 6L6 and philips ecc83 in, put SS recto (four diodes..nothing more), one greenback and one marshall vintage 30...set impedance to 16 ohm instead 8, high treble channel sounds something between my 50w bass and a jtm45 - 100 (think the wind cries mary) and normal channel sounds like eric..

yeah i roll the tone off a bit on the guitar for that cream tone

Here's a sample from my recent build -- from the workbench in fact (waiting on a red tolex head box)

http://forum.metroamp.com/download/file.php?id=8170" onclick="window.open(this.href);return false;

This is a stock build with stock magnetics and stock resistors. Sozo caps.

NOTE: No treble bypass cap at all.

2x12 Chinese-made ceramic Celestion Greenbacks in a Geezer Sound Company slant-front open-back cabinet.

Presence = 2-ish maybe? I forget. No higher than 4.
Bass = 2
Middle = 10
Treble = 10
Volume = 10 High Treble channel (not jumpered)

Les Paul Heritage 80 -- pickups were replaced with contemporary Duncan 59s. No pedals, just a cable. I think it's pretty easy to tell which pickup is being used. Nothing was recorded with both pickups.

This was with the guitar on about 4 for the neck pickup chords at the beginning, and wide open for the rest.

recorded with SM57 near cone edge

Ehhhh... it sure is a ball of fun to play. The bulk of the difference likely is due to the guitar itself.

The cool thing is that after above like 6 or 7, it doesn't get very much louder, it just inflates its balls. Setting to that transition point allows for very expressive playing because it gives that bit of squawk when you hit it harder, like goosing a stripper. I shoot for a bit above that and roll back the volume on the guitar just a bit so chords are a touch cleaner.